# IRPCObjectOperations.DownloadFile_Begin

Location: [gRPC API](https://developer.m-files.com/APIs/gRPC-API/index.md) > [Vault API](https://developer.m-files.com/APIs/gRPC-API/vault/index.md) > [Objects, versions, properties and files](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/index.md)

HTML version: https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile_Begin/

Badges: `Vault API / core` `read` `session or assertion` `idempotent` `returns metadata structure version`

Opens a download session for a file version and returns its ID, the content size and, on
request, its MD5 checksum.

- **Service:** [Objects, versions, properties and files](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/index.md) `MFiles.IRPCObjectOperations`
- **gRPC method:** `/MFiles.IRPCObjectOperations/DownloadFile_Begin`
- **HTTP (mf-http-grpc):** `POST /grpc/v1/download-file_-begin`
- **Request:** [`DownloadFile_BeginRequest`](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile_Begin/index.md#request)
- **Response:** [`DownloadFile_BeginResponse`](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile_Begin/index.md#response)
- **Book and level:** Vault API, core
- **Kind:** read
- **Session:** Required: a session (mfiles-session-id-bin metadata) or a session assertion (x-mf-session-assertion metadata).
- **Idempotent:** yes
- **Returns metadata structure version:** yes (in the mfiles-metadata-version-bin trailer)
- **Streaming:** none (unary)

<a id="remarks"></a>

## Remarks

Downloading a file takes three calls:

1. `DownloadFile_Begin` with the file's `obj_file_ver` and `prepare_file_for_downloading` true.
2. [DownloadFile_ReadBlock](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile_ReadBlock/index.md) with the
   returned `download_id`, from offset 0, until a block shorter than requested comes back. Blocks
   are at most 4 MiB.
3. [DownloadFile_Stop](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile_Stop/index.md). When the whole
   file was read in order from the start, the server has already closed the session; the call
   still succeeds, so always make it.

Take `obj_file_ver.file_ver` from the version information of the object
([File](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.File/index.md) `file_ver`). It must be a specific file version:
`FILE_VER_TYPE_LATEST` fails with "Not found. (File <id>-0 not found.)".

**Formats.** `FILE_FORMAT_NATIVE` downloads the file as stored. `FILE_FORMAT_PDF` and
`FILE_FORMAT_DISPLAY_ONLY_PDF` download a PDF rendition that the server creates if needed (for
example from Office files); `file_outline.size` is then the size of the PDF. `FILE_FORMAT_PLAIN_TEXT`
and `FILE_FORMAT_MARKDOWN` are not supported here ("The requested file format ... is not
supported."); use
[GetTextContentForFileWithFormat](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/GetTextContentForFileWithFormat/index.md).

**Checksum.** `file_outline.md5_checksum` is filled only when `need_checksum` is true; otherwise it
is 32 zeros. For the PDF formats the server currently returns the checksum of the native file,
not of the PDF, so do not verify a PDF download against it.

**Session.** A download session belongs to the login session that opened it, on the server that
opened it. An unused session is closed after about 10 minutes (server default).

<a id="request"></a>

## Request: DownloadFile_BeginRequest

> Nested message fields are expanded to depth 3; follow a type link for deeper levels and for the type's own page.

| Field | Type | Description |
|---|---|---|
| `obj_file_ver` | [`ObjFileVer`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjFileVer/index.md) | The object and the specific file version, as in `File.file_ver`. |
| `obj_file_ver.obj_id` | [`ObjID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjID/index.md) | The object that owns the file. |
| `obj_file_ver.obj_id.type` | `int32` | The object type ID, for example 0 for documents. In a lookup value, the value list ID (for a lookup to objects, the object type ID). |
| `obj_file_ver.obj_id.item_id` | [`ItemID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ItemID/index.md) | The ID of the object within its type, in `item_id.internal_id`. |
| `obj_file_ver.file_ver` | [`FileVer`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.FileVer/index.md) | The specific file version, as in `File.file_ver`. |
| `obj_file_ver.file_ver.file_id` | [`FileID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.FileID/index.md) | The file. |
| `obj_file_ver.file_ver.type` | [`FileVerType`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.FileVerType/index.md) | `FILE_VER_TYPE_SPECIFIC` for a file version number. Values: `FILE_VER_TYPE_UNINITIALIZED` (0), `FILE_VER_TYPE_LATEST` (1), `FILE_VER_TYPE_ANY` (2), `FILE_VER_TYPE_SPECIFIC` (3). |
| `obj_file_ver.file_ver.internal_version` | `int32` | The file version number. |
| `obj_file_ver.file_ver.external_repository_version` | `string` | Used only for files in external repositories. Leave empty. |
| `obj_file_ver.file_ver.external_repository_sort_key` | `int64` | Used only for files in external repositories. Leave 0. |
| `format` | [`FileFormat`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.FileFormat/index.md) | `FILE_FORMAT_NATIVE` (default), `FILE_FORMAT_PDF` or `FILE_FORMAT_DISPLAY_ONLY_PDF`. Values: `FILE_FORMAT_NATIVE` (0), `FILE_FORMAT_PDF` (1), `FILE_FORMAT_DISPLAY_ONLY_PDF` (2), `FILE_FORMAT_PLAIN_TEXT` (3), `FILE_FORMAT_MARKDOWN` (4). |
| `prepare_file_for_downloading` | `bool` | Must be true to download. False only checks the caller's access and records the file as accessed; `download_id` is then 0. |
| `need_checksum` | `bool` | True to get the MD5 checksum of the native file in `file_outline.md5_checksum`. |

<a id="response"></a>

## Response: DownloadFile_BeginResponse

> Nested message fields are expanded to depth 3; follow a type link for deeper levels and for the type's own page.

| Field | Type | Description |
|---|---|---|
| `download_id` | `int32` | The download session for `DownloadFile_ReadBlock` and `DownloadFile_Stop`. 0 if `prepare_file_for_downloading` was false. |
| `file_outline` | [`FileOutline`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.FileOutline/index.md) | The size of the content to download, in the requested format, and the checksum if requested. |
| `file_outline.size` | `int64` | The size of the content in bytes, in the downloaded format. |
| `file_outline.size_precision` | [`FileSizePrecision`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.FileSizePrecision/index.md) | The file size precision. If the file size precision is 'exact', the size can be used for reading the file content. If the precision is 'unknown', the size field should not be used at all. Values: `FILE_SIZE_PRECISION_EXACT` (0), `FILE_SIZE_PRECISION_ESTIMATE` (1), `FILE_SIZE_PRECISION_UNKNOWN` (2). |
| `file_outline.md5_checksum` | `string` | The MD5 checksum as 32 hexadecimal digits, if requested; 32 zeros otherwise. |
| `ov_ex` | [`ObjectVersionEx`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjectVersionEx/index.md) | The version information of the object that owns the file. |
| `ov_ex.version_info` | [`ObjectVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjectVersion/index.md) | Object Version information. |
| `ov_ex.version_info.version` | [`ObjVerVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjVerVersion/index.md) | The version number, as a specific version. |
| `ov_ex.version_info.display_version` | `string` | The version label to show, if it differs from the version number; empty otherwise. |
| `ov_ex.version_info.title` | `string` | The title (name) of the object in this version. |
| `ov_ex.version_info.is_single_file_object` | `bool` | True if the object is a single-file document, which has exactly one file. |
| `ov_ex.version_info.has_relationships_from_this` | `bool` | Note: this field is deprecated. True if relationships from this object version to one or more documents exist. |
| `ov_ex.version_info.has_relationships_to_this` | `bool` | Note: this field is deprecated. True if relationships from one or more documents to this object version exist. |
| `ov_ex.version_info.has_assignments` | `bool` | True if relationships from one or more assignments to this object version exist. |
| `ov_ex.version_info.last_modified_at_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | When the version was last modified, in UTC. |
| `ov_ex.version_info.files[]` | repeated [`File`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.File/index.md) | The files of this version. Each `file_ver` can be passed to `DownloadFile_Begin`. |
| `ov_ex.version_info.object_version_flags` | [`OBJVERFLAGS`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.OBJVERFLAGS/index.md) | Bit flags that provide additional information on the object version. |
| `ov_ex.version_info.class_id` | `int32` | The class ID of the version. |
| `ov_ex.version_info.version_guid` | `string` | The GUID of this version. |
| `ov_ex.version_info.base_properties[]` | repeated [`PropertyValue`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.PropertyValue/index.md) | Not filled by the object read methods; read the property values with `GetObjectVersionAndPropertiesOfMultipleObjects` or `GetProperties`. |
| `ov_ex.version_info.primary_file` | [`FileID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.FileID/index.md) | File ID of the primary file of a multi-file object, if the object is a multi-file object. |
| `ov_ex.object_info` | [`ObjectLevelInfo`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjectLevelInfo/index.md) | Object-level information. |
| `ov_ex.object_info.obj_id` | [`ObjID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjID/index.md) | The object type and ID of the object. |
| `ov_ex.object_info.external_id_status` | [`ExtIDStatus`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.ExtIDStatus/index.md) | The status of this object's external ID. Values: `EXT_IDSTATUS_UNKNOWN` (0), `EXT_IDSTATUS_EXTERNAL` (1), `EXT_IDSTATUS_INTERNAL` (2), `EXT_IDSTATUS_DISCARDED` (3), `EXT_IDSTATUS_NOT_AVAILABLE` (4), `EXT_IDSTATUS_EXTERNAL_REDUCED` (5). |
| `ov_ex.object_info.external_id` | `string` | The external ID (display ID) of this object. unset means that the external ID is the same as the internal ID. |
| `ov_ex.object_info.checked_out_version` | [`ObjVerVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjVerVersion/index.md) | The version that is checked out. Version number 0 if the object is not checked out. |
| `ov_ex.object_info.checked_out_to_user_id` | `int32` | The ID of the user who has the object checked out. |
| `ov_ex.object_info.checked_out_to_user_name` | `string` | The user name of the user who has the object checked out. |
| `ov_ex.object_info.checked_out_to_host_name` | `string` | The host name of the computer to which the object was checked out. |
| `ov_ex.object_info.checked_out_at_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | The timestamp of the moment the object was checked out. |
| `ov_ex.object_info.checked_in_version` | [`ObjVerVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjVerVersion/index.md) | The latest checked-in version. |
| `ov_ex.object_info.created_at_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | The time when the object was created (same as the PROPERTYDEF_CREATED propertyvalue). |
| `ov_ex.object_info.accessed_by_me_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | Accessed by me timestamp. Parallel operations may cause slight inconsistencies in the returned timestamp in rare cases and the precise value shouldn't be relied upon. The observed timestamp may even roll back. |
| `ov_ex.object_info.guid` | `string` | The object GUID, in braces. The same value as `GetObjectGUID` returns. |
| `ov_ex.object_info.options` | [`ITEMFLAGS`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ITEMFLAGS/index.md) | Bit flags that provide additional information on the object (e.g. is the object deleted or a stub). |
| `ov_ex.object_info.original_vault_guid` | `string` | The GUID of the vault in which the object was originally created. |
| `ov_ex.object_info.original_vault_obj_id` | [`ObjID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjID/index.md) | The original objid in the vault in which the object was originally created. |
| `ov_ex.object_info.associated_view_id` | [`ItemID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ItemID/index.md) | Identifies the view associated with this object if any. |
| `ov_ex.object_info.external_repository_icon_id` | `string` | If not null, identifies the icon of the object. Currently applicable only to unmanaged objects. |
| `ov_ex.object_info.primary_view_id` | [`ItemID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ItemID/index.md) | If not null, identifies the primary view of the object that is also the default opening location of the object. Currently applicable only to unmanaged objects. |
| `ov_ex.object_info.capabilities` | [`OBJECTCAPABILITYFLAGS`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.OBJECTCAPABILITYFLAGS/index.md) | Bit flags that provide information on the object capabilities. |
| `updated_objects[]` | repeated [`ObjectVersionEx`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjectVersionEx/index.md) | Information about objects that were also updated during the operation. (represented by ObjectVersionEx structs.) |
| `updated_objects[].version_info` | [`ObjectVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjectVersion/index.md) | Object Version information. |
| `updated_objects[].version_info.version` | [`ObjVerVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjVerVersion/index.md) | The version number, as a specific version. |
| `updated_objects[].version_info.display_version` | `string` | The version label to show, if it differs from the version number; empty otherwise. |
| `updated_objects[].version_info.title` | `string` | The title (name) of the object in this version. |
| `updated_objects[].version_info.is_single_file_object` | `bool` | True if the object is a single-file document, which has exactly one file. |
| `updated_objects[].version_info.has_relationships_from_this` | `bool` | Note: this field is deprecated. True if relationships from this object version to one or more documents exist. |
| `updated_objects[].version_info.has_relationships_to_this` | `bool` | Note: this field is deprecated. True if relationships from one or more documents to this object version exist. |
| `updated_objects[].version_info.has_assignments` | `bool` | True if relationships from one or more assignments to this object version exist. |
| `updated_objects[].version_info.last_modified_at_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | When the version was last modified, in UTC. |
| `updated_objects[].version_info.files[]` | repeated [`File`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.File/index.md) | The files of this version. Each `file_ver` can be passed to `DownloadFile_Begin`. |
| `updated_objects[].version_info.object_version_flags` | [`OBJVERFLAGS`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.OBJVERFLAGS/index.md) | Bit flags that provide additional information on the object version. |
| `updated_objects[].version_info.class_id` | `int32` | The class ID of the version. |
| `updated_objects[].version_info.version_guid` | `string` | The GUID of this version. |
| `updated_objects[].version_info.base_properties[]` | repeated [`PropertyValue`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.PropertyValue/index.md) | Not filled by the object read methods; read the property values with `GetObjectVersionAndPropertiesOfMultipleObjects` or `GetProperties`. |
| `updated_objects[].version_info.primary_file` | [`FileID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.FileID/index.md) | File ID of the primary file of a multi-file object, if the object is a multi-file object. |
| `updated_objects[].object_info` | [`ObjectLevelInfo`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjectLevelInfo/index.md) | Object-level information. |
| `updated_objects[].object_info.obj_id` | [`ObjID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjID/index.md) | The object type and ID of the object. |
| `updated_objects[].object_info.external_id_status` | [`ExtIDStatus`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.ExtIDStatus/index.md) | The status of this object's external ID. Values: `EXT_IDSTATUS_UNKNOWN` (0), `EXT_IDSTATUS_EXTERNAL` (1), `EXT_IDSTATUS_INTERNAL` (2), `EXT_IDSTATUS_DISCARDED` (3), `EXT_IDSTATUS_NOT_AVAILABLE` (4), `EXT_IDSTATUS_EXTERNAL_REDUCED` (5). |
| `updated_objects[].object_info.external_id` | `string` | The external ID (display ID) of this object. unset means that the external ID is the same as the internal ID. |
| `updated_objects[].object_info.checked_out_version` | [`ObjVerVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjVerVersion/index.md) | The version that is checked out. Version number 0 if the object is not checked out. |
| `updated_objects[].object_info.checked_out_to_user_id` | `int32` | The ID of the user who has the object checked out. |
| `updated_objects[].object_info.checked_out_to_user_name` | `string` | The user name of the user who has the object checked out. |
| `updated_objects[].object_info.checked_out_to_host_name` | `string` | The host name of the computer to which the object was checked out. |
| `updated_objects[].object_info.checked_out_at_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | The timestamp of the moment the object was checked out. |
| `updated_objects[].object_info.checked_in_version` | [`ObjVerVersion`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjVerVersion/index.md) | The latest checked-in version. |
| `updated_objects[].object_info.created_at_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | The time when the object was created (same as the PROPERTYDEF_CREATED propertyvalue). |
| `updated_objects[].object_info.accessed_by_me_utc` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | Accessed by me timestamp. Parallel operations may cause slight inconsistencies in the returned timestamp in rare cases and the precise value shouldn't be relied upon. The observed timestamp may even roll back. |
| `updated_objects[].object_info.guid` | `string` | The object GUID, in braces. The same value as `GetObjectGUID` returns. |
| `updated_objects[].object_info.options` | [`ITEMFLAGS`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ITEMFLAGS/index.md) | Bit flags that provide additional information on the object (e.g. is the object deleted or a stub). |
| `updated_objects[].object_info.original_vault_guid` | `string` | The GUID of the vault in which the object was originally created. |
| `updated_objects[].object_info.original_vault_obj_id` | [`ObjID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ObjID/index.md) | The original objid in the vault in which the object was originally created. |
| `updated_objects[].object_info.associated_view_id` | [`ItemID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ItemID/index.md) | Identifies the view associated with this object if any. |
| `updated_objects[].object_info.external_repository_icon_id` | `string` | If not null, identifies the icon of the object. Currently applicable only to unmanaged objects. |
| `updated_objects[].object_info.primary_view_id` | [`ItemID`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ItemID/index.md) | If not null, identifies the primary view of the object that is also the default opening location of the object. Currently applicable only to unmanaged objects. |
| `updated_objects[].object_info.capabilities` | [`OBJECTCAPABILITYFLAGS`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.OBJECTCAPABILITYFLAGS/index.md) | Bit flags that provide information on the object capabilities. |

<a id="related"></a>

## Related methods

- [DownloadFile_ReadBlock](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile_ReadBlock/index.md): Reads a block of a file from a download session.
- [DownloadFile_Stop](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile_Stop/index.md): Closes a download session.
- [GetTextContentForFileWithFormat](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/GetTextContentForFileWithFormat/index.md): Gets the text content of a file version as plain text or Markdown, and reports which format was produced.
- [DownloadFile](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCObjectOperations/DownloadFile/index.md): Not available over native gRPC: the server answers "Not implemented.". Used by the M-Files HTTP gateway.